首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   7732篇
  免费   432篇
  国内免费   56篇
管理学   812篇
民族学   117篇
人口学   131篇
丛书文集   529篇
理论方法论   420篇
综合类   4623篇
社会学   700篇
统计学   888篇
  2024年   21篇
  2023年   114篇
  2022年   134篇
  2021年   182篇
  2020年   215篇
  2019年   176篇
  2018年   206篇
  2017年   278篇
  2016年   258篇
  2015年   268篇
  2014年   250篇
  2013年   835篇
  2012年   526篇
  2011年   499篇
  2010年   301篇
  2009年   250篇
  2008年   384篇
  2007年   525篇
  2006年   508篇
  2005年   457篇
  2004年   381篇
  2003年   333篇
  2002年   265篇
  2001年   246篇
  2000年   178篇
  1999年   84篇
  1998年   59篇
  1997年   41篇
  1996年   49篇
  1995年   40篇
  1994年   32篇
  1993年   21篇
  1992年   14篇
  1991年   15篇
  1990年   18篇
  1989年   13篇
  1988年   10篇
  1987年   7篇
  1986年   1篇
  1985年   2篇
  1984年   8篇
  1983年   5篇
  1982年   3篇
  1981年   3篇
  1980年   1篇
  1979年   2篇
  1978年   1篇
  1977年   1篇
排序方式: 共有8220条查询结果,搜索用时 17 毫秒
1.
In the current investigation, idiosyncratic deals (i-deals; individualized work arrangements) are modeled as differentiated resources that shape leader-member exchange (LMX) relationships in workgroups. We integrate literature on leader-member exchange (LMX) with research on i-deals to argue that employee evaluations of i-deals received from the grantor –typically the leader- enhance employee perceptions of LMX, which in turn become instrumental in generating positive performance outcomes. Furthermore, because workgroup characteristics have potential implications on the relationship between a deal grantor and the deal recipient, drawing upon social identity theory of leadership, we reason that the i-deals-LMX relationship is affected by the overall value congruence among the group members. Cross-level moderated mediation analyses on multi source data obtained from 289 employees nested in 60 workgroups showed that the mediational role of LMX in the i-deals to performance outcomes relationship was weaker in high value congruence groups.  相似文献   
2.
Africa’s developing economies remain in critical need for leadership. This paper asserts that Africa’s new growth opportunities rest with leadership that could champion organizational performance, innovativeness, and good ethics among others. A review of extant literature on leadership development programmes (LDPs) was done to examine possible initiatives that leadership developers can use to influence leadership practices in Africa. This paper proposes that in Africa, LDPs can be used to inculcate authentic leadership practices and enhance networking and acquisition of innovative skills among others. Furthermore, LDPs could target the youth considering them as an investment into tomorrow’s leadership talent pool. The paper suggests that Africa’s niche for the global highway rests in contextualization of LDPs from other regions to Africa’s unique environment.  相似文献   
3.
机械产品的设计一直注重于市场需求和产品功能的开发,随着科学和技术的发展,环境因素变得越来越重要。 提出一种基于功能一环境一结构分析( FESA)与TRIZ的机械产品创新设计方法,通过分析机械产品结构之间的功能要素 以及功能要素与环境要素的相互作用关系,确定机械产品中存在的问题。建立根原因模型图,寻找结构设计上的不足和 缺陷,利用TRIZ创新理论来实现机械产品的改进创新。通过污水处理系统的创新设计实例验证了该方法的可行性。  相似文献   
4.
Participant retention is a key factor in determining the success of longitudinal research. Challenges in re-locating and retaining participants over the long term are major issues for researchers working with young people who face adversity and experience frequent changes in circumstances. This article reports on a study of vulnerable young people and their transition into adulthood. Rather than the more conventional schedule-based approach to locating and re-interviewing young people, a relational process, the ‘right time’ framework, was used to facilitate young people's involvement in the study. Embedded in the ‘right time’ framework is recognition of the diverse and fluctuating circumstances that shape young people's availability for interviews. Several case examples are considered which amplify the way that the ‘right time’ framework allowed the research to navigate around these circumstances. The case examples highlight the value young people attached to being involved in the research, the influence on the ‘right time’ of wider relational tensions for young people and the need to negotiate researcher status as a different sort of adult. The ‘right time’ framework contributed to a high retention rate in the study generating a more representative sample and enhancing the subsequent data analysis by providing valuable insights into the lives of these vulnerable young people.  相似文献   
5.
针对目前金属疲劳裂纹扩展检测方法存在效率低、操作繁琐、精度不高,不能实现实时性等缺点,文章提出了基 于机器视觉的裂纹检测方法。根据金属疲劳裂纹扩展试验过程中裂纹图像的采集要求,设计了摄像头位置可自动调整 的疲劳裂纹图像采集系统,包括摄像头安装运动装置,裂纹图像采集装置以及摄像头运动控制系统。图像采集装置由高 分辨率黑白面阵CCD摄像头、光学镜头,光源照明装置和图像采集卡组成,前3者安装在摄像头支架上,与摄像头运动 装置相连。摄像头运动装置中的X,Y,,Z轴运动机构由步进电机带动滚珠导轨机构。在基于ARM技术的运动控制系统 的控制下摄像头可沿X,Y,,Z轴作高精度直线运动,实现和试件之间精确位置的调整。实验结果表明,所设计的系统可 采集到疲劳裂纹扩展试验过程中高清晰度、高分辨率的试件裂纹图像,满足下一步裂绞尺寸计算的要求;摄像头运动定 位精度可达到0. 02 mm,满足精确的系统聚焦、位置调整、跟踪采集的要求。  相似文献   
6.
通过对5位国家级教学名师的自述报告进行三级编码和主题凝练,研究发现国家级教学名师作为教师队伍的杰出代表,在其专业发展过程中养成了许多优秀品质。例如:教学方面注重实践、考虑周全,师德方面以德施教、追求卓越,科研方面以教带研、实现创新。国家级教学名师优秀品质的养成通常经历了漫长而曲折的过程,不仅需要精神与物质力量的共同推动,还需要家庭、学校和社会各环境要素的相互促进,以及社会取向养成方式和个人取向养成方式的互相配合。深入探究国家级教学名师的优秀品质及其养成之道,可以为教师专业发展提供借鉴与启示。  相似文献   
7.
The concept of reciprocal coordinate subtangent (RCST) has been used as a useful tool to study the monotone behavior of a continuous density function and for characterizing probability distributions. In this paper, we propose a non-parametric estimator for RCST based on the censored dependent data. Asymptotic properties of the estimator are established under suitable regularity conditions. A simulation study is carried out to examine the performance of the estimator. The usefulness of the estimator is also examined through a real data.  相似文献   
8.
Modern analytical models for anti-monopoly laws are a core element of the application of those laws. Since the Anti-Monopoly Law of the People’s Republic of China was promulgated in 2008, law enforcement and judicial authorities have applied different analytical models, leading to divergent legal and regulatory outcomes as similar cases receive different verdicts. To select a suitable analytical model for China’s Anti-Monopoly Law, we need to consider the possible contribution of both economic analysis and legal formalism and to learn from the mature systems and experience of foreign countries. It is also necessary to take into account such binding constraints as the current composition of China’s anti-monopoly legal system, the ability of implementing agencies and the supply of economic analysis, in order to ensure complementarity between the analytical model chosen and the complexity of economic analysis and between the professionalism of implementing agencies and the cost of compliance for participants in economic activities. In terms of institutional design, the models should provide a considered explanation of the legislative aims of the law’s provisions. It is necessary, therefore, to establish a processing model of behavioral classification that is based on China’s national conditions, applies analytical models using normative comprehensive analysis, makes use of the distribution rule of burden of proof, improves supporting systems related to analytical models and enhances the ability of public authorities to implement the law.  相似文献   
9.
应用于交易领域的智能合约融入区块链技术,以代码形式表现,可实现合同履行的自动化和不可逆,超越了传统意义上的合同模式.自助行为说、代理说将智能合约视为对合同过程的外部增强,是侧面功能的法律阐释,并未完全捕捉到实质.智能合约并不一定跨越整个合同过程,也可仅是合同过程某个方面或某个阶段.法律意义上的智能合约不是合同新类型,而是合同关系形式的新发展,即当事人缔结和履行合同的新形式,合同性质未发生实质变化.智能合约满足特定要件构成特殊的书面形式,具有"书面形式+自动履行"功能的特质.民事主体通过智能合约形式订立合同应遵守《民法典》等现行法律的具体规则,以保证合同依法成立与生效.智能合约不等同于具有法律效力的合同,认定其效力应结合智能合约应用中的具体问题展开具体分析.从立法上确认智能合约,在符合国家现有法律、政策基础上编写和应用,实现形式的合法化、内容的规范化是该技术谋求长远发展的保障.技术起步的现阶段,纸质合同、一般电子合同与智能合约在不同方面发挥协作作用,会在未来一段时间内成为民事交往、商业交易的主要状态.  相似文献   
10.
在装备采购中,由于需求单位地域分布和担负的任务各不相同,对装备的品种、数量、时限要求也就不一样,如何使装备采购科学化、合理化,是一个涉及多变量、多目标的复杂系统问题。在综合考虑装备采购各项因素的基础上,构建多约束条件下的多目标模糊指派模型,提出了基于遗传算法的解决方案,最后通过案例进行仿真实验,验证该算法的可行性和有效性,解决了采用传统优化方法难以解决的装备采购优化决策问题。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号